g-total
Total solar energy transmission through a window and sun blind together.

g-value
The sum of primary and secondary transmittance. The G-value indicates the total solar energy transmission through the window or sunblind. Indicated by a value between 0 and 1 or as a percentage. The higher the value, the more energy passes through.

Insulating glass
A window structure using two or three panes of glass. There is often gas (for example argon) between the panes and a low emissive layer in order to prevent the absorption of heat radiation (which prevents heat loss).